Abstract In order to achieve high resonance frequencies and quality factors of pyrolytic carbon MEMS string resonators the resonator material needs to have a large tensile stress. In this study, the influence of pyrolysis temperature, dwell time and ramping rate on the residual stress in thin pyrolytic carbon films is investigated with the bending plate method. The results show that the pyrolysis temperature is the most important parameter for tailoring the residual stress, with a transition from tensile stress at temperature below 800 o C to compressive stress at temperatures above 800 o C. Two kinds of photoresist: positive (AZ5214E) and negative (SU-8) and different pyrolysis conditions are used to fabricate pyrolytic carbon string resonators at variable pyrolysis conditions. The best performance is obtained for devices with a length of 400 μm fabricated at a pyrolysis temperature of 700 o C, ramping rate of 30 o C/min and 10 min dwell time corresponding to the conditions for maximum tensile stress in pyrolytic carbon thin films. The optimized pyrolytic carbon string resonators have resonant frequencies above 300 kHz and quality factors (Q) in the order of 10 4 , which is suitable for their application as nanomechanical sensors.

中文翻译：

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用于制造纳米机械弦谐振器的热解碳中的剪裁应力

摘要 为了实现热解碳MEMS弦谐振器的高谐振频率和品质因数，谐振器材料需要具有较大的拉应力。本研究采用弯板法研究了热解温度、停留时间和升温速率对热解碳薄膜中残余应力的影响。结果表明，热解温度是调整残余应力的最重要参数，从低于 800 o C 温度的拉应力转变为高于 800 o C 温度的压应力。两种光刻胶：正性（AZ5214E）和负（SU-8）和不同的热解条件用于在可变热解条件下制造热解碳弦谐振器。在 700 o C 的热解温度、30 o C/min 的升温速率和 10 分钟的停留时间下制造的长度为 400 μm 的器件获得最佳性能，对应于热解碳薄膜中最大拉伸应力的条件。优化的热解碳弦谐振器具有高于 300 kHz 的谐振频率和 10 4 数量级的品质因数 (Q)，适用于它们作为纳米机械传感器的应用。